Cone loud-speaker



Feb. 5, 1929.

7 1,700,805 R. W. MORRIS CONE LOUD SPEAKER Filed June 30, 1925 2 INVENTOR L l. Wflfwwas ATTORNEY Patented Fe b. 5.1 29.

. UNITED STA Bonnier w.

PATENT OFFICE.

MORRIS, OF ROSLYN, NEW YORK,' ASSIGI IOR TO AMERICAN TELEPHONE LAND TELEGRAPH COMI'ANY; A CORPORATION OF NEW YORK.

ooNE LOUD-SPEAKER.

' Application filed June 30, 1925. Serial No. 40,660.

This invention relates to loud speaking telephone receivers, and more particularly, to loud speaking telephone receivers of the cone type. I

The ,chief advantage of the cone loud speaker over the horn type of loud speaker is' that the former provides a large diaphragm, which produces greater efficiency forthe lower frequencies than is the case with the horn type unless the horn is made so large that it would be inconvenient for'prtlinary residence use.

One type of cone loud speaker has the shape of a symmetrical, circularor right cone. A serious objection to this type is that 'the recc iv'erhas natural periods of vibration in the operating range of 0 to- 5,000 cycles.

. This objection has'been overcome in some cases by giving the loud speaker an asyni' metrical construction-the so -called'ell1ptical cone, in which the various segments of the cone have difi erent natural frequencies, and theinstru'ment is free from resonant eftects. The asymmetrical cone, however, is objectionable on two grounds, first, that it is bulky and not pleasing in. appearance, and second, that the loadon the driving mechanism is unbalanced.

The object of applicant-s invention de' scribed and claimed in this application is the production of a loud speaker which is not open to the first objection and yet meets the requirement that the resonant effects be eliminated. I

'In an application filed of even date herewith and-numbered 40,661 applicant describes and claims a symmetrical cone loud speaker in which the load on the driving mechanism is balanced. i l

The invention which is the subject of this application will be-clearly understood when the following description is read with reference'to the accompanyingdrawing, which shows one desirable embodiment of the invention. Figure 1 of the drawing is a view of the receiver from the cone side, and Fig.

2jis a sectional view on the line 22 of Fig.

1 in'the direction indicated by the arrows.

With referencegto the details of the drawing, the'coneand the frusto-cone are circular, but the ortionS of the cone and the portion .4 ofthe trusto cone are so formed as to overfcome the objectionable resonant eilccts foundin the ordinary circular receiver. The wall :ottlie cone over the portion 3 and the wall of p the frusto-cone over the portion 4 are constr'ucted'so as to have a continuusly varying thickness, the greatest thickness in each case being at the base. In Fig. ,1 the heavier shading indicates the greater thickness. In Fig. 2 the thickness-oi? the material is exaggerated and the continuous variation clearly shown.

The continuously varying thickness may be v ously varying thickness may be described as a COIllllDHOHSlY varying loading of a segment of the cone and a segment of the trusto-cone.

It is obvious to those skilled in the art that the form of applicants receiver overcomes the difiiculty of natural periods of vibration in the voice band trequencies since the different portions of the cone and the frustocone will have different natural frequencies and the device will be free from any resonant eflect.

What is claimed is: I 1. A cone loud speaking receiver having The variation of thickness obtained a portion of its wall of varying thickness'and the balance of thewall of unvarying thickness.

2. Asymmetrical cone loud speaking receiver havinga portion of its wall of varyin thickness and the balance of the wall 0 unvarying thickness. I

3. A cone-loud speaking receiver having a portion of its wall of continuously varying thickness, the greatest thickness being at the I base of the cone, and the balance of the wall of. unva-rying thickness.

4. A cone-loud speaking receiver having a segment of its Wall of continuously varying 7 thickness; the greatest thickness being at the base of the cone.

5. A loud, speaking receiver comprising a conical portion and a trusto-conical portion, a part of each of said portions having a varying thi .rness and the balance of each of said portions having an unvarying thickness.

. 6. A loud spez-iking receiver i'zompiislng a iiU conical portion and a. frusto-conical portion, a segment of each of said portions having a continuously varying thickness.

7. A symmetrical loud speaking receiver comprising a conical portion and a frustoconical portion, a part of each of said portions having a varying thickness and the balance of each of said portions having an unvarying thickness.

8. A loud speaking receiver comprising a conical portion and a frusto-conical portion, a segment of each of said portions having a contmuously varying thickness, the greatest thickness being at the bases of the cone and the frusto-cone.

9. A loud speaking receiver comprising a conical portion and a frusto-conical portion, a part of each of said portions having a continuously varying thickness, the greatest thickness being atthe bases of the cone and the frusto-cone, and the balance of each of said portions having an unvarying thickness.

10. A cone loud speaking receiver in which no annular section is of uniform thickness.

11. A cone loud speaking receiver in which one portion has varying loading and the balance of the receiver has unvarying loading.

a part of each of said portions having continuously varying loading.

14. A loud speaking receiver comprising a conical portion and a frusto-conical portion, a part of each of said portions having varying loading and the balance of each portion having unvarying loading.

15. A loud speaking receiver comprising a conical portion and a frusto-conical portion, a part of each of said portions having con tinuously Varying mass per unit area.

16. A loud speaking receiver comprising a conical portion and a frusto-conical portion, a part of said portions having continuously varying mass per unit area and the balance of each portion having unvarying mass per unit area.

In testimony whereof, I have signed my name to this specification this 29th day of 7 June, 1925.

ROBERT W. MORRIS. 

